1. Field of the Invention
This invention relates in general to high pressure product swivels used in offshore floating, production and/or storage systems which transfer hydrocarbon fluids from a geostationary turret to a rotatable vessel. In particular the invention is applicable for high pressure swivels with radially mounted seals which require close running fits between stationary and rotatable housings.
2. Description of the Prior Art
High pressure swivels with radially mounted seals between closely spaced inner and outer housings are known in the art of product swivel design. In some circumstances, the temperature of the inner housing of the swivel can rise to a higher level than that of the outer housing. As a result, because of the difference in the thermal expansion of the inner and outer housing, a large reduction in radial clearance between the two housings can result with probable seizing of the sliding surfaces between the two housings.
A primary object of the invention is to provide an automatic temperature control system for equalizing the temperature between the inner and outer housings of a high pressure product swivel.
Another object of the invention is to provide an improved product swivel with a control system which prevents detrimental large temperature differences during operation between inner and outer housings.
Another object of the invention is to provide an improved product swivel with an automatic temperature control system with resulting smaller internal clearances and improved seal function.
Another object of the invention is to provide an improved product swivel with an automatic temperature control system which prevents high friction torque in bearings between stationary and rotating housings even in circumstances of high temperature of one of the housings.
Another object of the invention is to provide a fluid transfer system for an offshore floating production and/or storage vessel which has a high pressure fluid system with an automatic temperature control system which acts to prevent disastrous failure of the swivel torque arm and connected piping of the transfer system.
The objects identified above, along with other features and advantages of the invention are incorporated in a fluid swivel and automatic temperature control system which includes a swivel with an outer housing and an inner housing. The outer housing is arranged and designed for rotation with the vessel as the vessel weathervanes about the geostationary turret. The inner housing of the turret is mounted on the stationary turret. An automatic temperature control system includes temperature measurement devices on the inner and outer housings, a heating device on the outer housing and a temperature regulating mechanism responsive to the temperature measurement of the inner and outer housing to regulate the temperature of the outer housing.